Artificial tooth.



No. 354,842. PATENTED MAY.23,1907. -l

PPPPPPPPPPPPPPPPPPPPPPPPP J.RAMSPERGBR.

- ARTIPIGIAL'TOOTH.

UNITED SrlA'IES PATENT orrron.

Specication of Letters Patent.

- I Patented May 28, 1907.

Application filed November 8,1906. Serial No. 342,520.

To all whom t may 00u/cern.:

Be it known that I, JOSEPH RAMSPERGER, a citizen of the United States,residing at York, in the county of York, State of Pennsylvania, haveinvented certain new and useful Improvements in Artificial Teeth; and Ido hereby declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to make and use the same.

This invention relates to improvements in artificial teeth andparticularly to improve ments in the means for securing the dowel pinsin the teeth.

It has been found in practice that a dowel pin cannot be made to stay inan ordinary straight hole forthe reason that the friction is notsufficient and if the fit is made sufficiently close to insure againstthe pin pulling out, then there is danger of cracking the tooth inforcing the pin into place. Various methods have been proposed forsecuring the pins by soldering them to plates baked into the teeth, butsuch plates must be of platinum because of the necessity of refractori-Vness and preventionof discoloration of the teeth. Platinum plates areexpensive and in a factory wherermillions of teeth are manufactured in ayear, the aggregate expense is enormous. It has been found that the bestmethod for holding the pins in the teeth is to enlarge the inner end ofthe holes or recesses that receive the pins and then rovide the ins withheads that fill the en argements. It is desirable that the heads of thepins be of solder because of the cheapness of the material and of theoperation. It is found in practice, however, that a simple inwardlyenlarged cavity in a porcelain tooth cannot be filled with solder as ahead for a pin for the reason that the solder when melted, instead offlowing into close contact with the wall of the enlargement, clings tothe pin and follows along it outwardly of the recess. It has beenproposed to line the recess and its enlargement with an inwardlyexpanded platinum tube, but both the material and the process areexpensive. Such a lining has for its object to provide a metal surfaceto which the solder will cling so that the enlargement may be lled withsolder.

The object of the present invention is to provide a tooth wherein theenlarged portion of an inwardly enlarged pin-receiving recess in thetooth will be provided with a thin metal lining having an exteriordiameter greater than the diameter of the unlined portion of the recess,to which lining the melted solder will flow and cling and by which itwill be held within the enlargement 'of the cavity to completely fillthe cavity the tooth showing the two core-pins and accompanying parts.Fig. 3 is a longitudinal section through the tooth with the lining inplace and ready for the pin. Fig. 4 is aview similar to Fig. 3 showingthe complete tooth ywith the pin in place. The article can probably bestbe explained or described by detailing the method of forming it.

Referring now to the drawings, 1 designates a common form of mold forforming a false tooth. From one member of the mold there project twocore-pins 3, the free end of each of which pins is slightly reduced indiameter as shown at 4 to receive a head 5. The head may be made of woodor paper or other combustible material and has a diameter slightlygreater than the major diameter of the pin. In the present process, theperiphery of the head is provided with an encircling tube or band 6 ofplatinum or other refractory metal. After .the core-pin has been thusequipped, the plastic 'material for the tooth proper 1s placed in themold and after having the tooth biscuited it is removed from the mold.The heat incident to the subsequent baking burns out the combustiblehead of the core-pin so that the tooth is provided with a recess orrecesses, as the case may be, each recess being inwardly enlarged orenlarged at its inner end, the enlarged portion being provided with alining of metal. The metal is preferably platinum, although it may be ofsome other refractory metal. The combustible head of the core-pin beingof greater diameter than the major portion of the pin, the inner endportion of the cavity is of greater diameter than the outer end portionvnotwithstanding its metal lining.

ros

A tooth thus produced may have a pin or pins 7 soldered into its cavityor cavities in any desired manner such as by dropping a small particleof solder into each cavity, then placing the pin in the cavity to restupon the solder and then subjecting the entire tooth With its pin andsolder to su'flicient heat to melt the solder and cause it to unite withthe pin and iill up the enlarged portion of 1o the cavity either unitingcontinuously or not With the metal lining of the enlarged portion of thecavity as shown at 12.

The advantages in this particular type of tooth are that the platinum isreduced to a very small quantity, `first by reason of being only aboutone-half the length necessaryT When a tube is used that reaches from thebottom of the cavity to the face of the tooth, and secondly by reason ofthe fact that as the lining does not necessarily form an an.- chor, butmerely a surface to Which the solder will flovv, it may be very thin andin fact be platinum foil. Furthermore in the completed tooth With itspin or pins, the platinum lining does not necessarily act as an anchorfor the pin or pins but merely provides a lining for the enlargement ofthe cavity, Which lining has an a'flinity for solder so that the solderl2 While uniting With the 3o pins 7 to form a head, Will How to thelining and completely fill up the enlargement of the cavity and thushold the pin securely through the medium of the head alone, ifnecessary.

Vhat is claimed is:

l. As an article of manufacture, an artiiicial tooth having apin-receiving cavity therein, the inner end portion of Which isenlarged, and a sheet metal lining against the 40 side Wall only of theenlarged portion of the cavity, the remaining part of the cavity bemgunlined, and the internal diameter of said lining being greater than thediameter of the unlined portion of the cavity.

2. As an article of manufacture, an artificial tooth having apin-receiving cavity therein, the inner end portion of which isenlarged, and a sheet metal lining against the side Wall only of theenlarged portion of the cavity, the remaining part of thc cavity bcingunlined, and the internal diameter of said lining being greater than thediameter of the unlined portion of the cavity, a pin inserted in thecavity and having a solder head united. thereto and to said lining, andfilling the enlarged portion of the cavity.

3. As an article of manufacture, an artificial tooth having apin-receiving cavity therein, the inner end portion of which isenlarged, and a lining of metal foil against the side Wall only of theenlarged portion of the cavity, the remaining part of the cavity beingunlined, and the internal diameter of said. lining being greater thanthe diameter of the unlined portion of the cavity.

4. As an article of inanufacture, an artiiicial tooth having apin-receiving cavity therein, the inner end portion of which isenlarged, and a lining of metal foil against the side Wall only of theenlarged portion of the cavity, the ren'iaining part of the cavity bvingunlined., and the internal diameter of said lining being greater thanthe diameter of the i unlined portion of the c: vity, a pin inserted inthe cavity and having a solder head united. thereto and to said lining,and iilling thc enlarged portion of the cavity.

ln testimony whereof, I allix my signature, in presence of twowitnesses.

JOSEPH RAMSPE ltGlllt.

litnesses B. M. PENTZ, A. J. BRENNEMAN.

